interface Animal {
    void shout();
}
class Cat implements Animal{

    @Override
    public void shout() {
        System.out.println("喵喵喵");

}
class Dog implements Animal {

    public void shout() {
        System.out.println("汪汪汪");
    }
}
public static class Example13 {
    public static void main(Animal animal) {
        Cat cat = (Cat) animal;
        cat.shout();
        cat.shout();

    }
}
}